<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Fulfilling Square Spinner</title>
    <style>
      .fulfilling-square-spinner , .fulfilling-square-spinner * {
        box-sizing: border-box;
      }

      .fulfilling-square-spinner {
        height: 50px;
        width: 50px;
        position: relative;
        border: 4px solid #ff1d5e;
        animation: fulfilling-square-spinner-animation 4s infinite ease;
      }

      .fulfilling-square-spinner .spinner-inner {
        vertical-align: top;
        display: inline-block;
        background-color: #ff1d5e;
        width: 100%;
        opacity: 1;
        animation: fulfilling-square-spinner-inner-animation 4s infinite ease-in;
      }

      @keyframes fulfilling-square-spinner-animation {
        0% {
          transform: rotate(0deg);
        }

        25% {
          transform: rotate(180deg);
        }

        50% {
          transform: rotate(180deg);
        }

        75% {
          transform: rotate(360deg);
        }

        100% {
          transform: rotate(360deg);
        }
      }

      @keyframes fulfilling-square-spinner-inner-animation {
        0% {
          height: 0%;
        }

        25% {
          height: 0%;
        }

        50% {
          height: 100%;
        }

        75% {
          height: 100%;
        }

        100% {
          height: 0%;
        }
      }
    </style>
</head>
<body>

<div class="fulfilling-square-spinner">
  <div class="spinner-inner"></div>
</div>

</body>
</html>
